Gold-saving device



(No Model.)

J. MAIT. GOLD SAVING DEVICE.

Patented Apr. 27, 1897;

NITED STATES JOSEPH MAIT, OF OAKLAND, CALIFORNIA.

GOLD-SAVING DEVICE.

SPECIFICATION forming part of Letters Patent No. 581 ,425, dated April 27, 1897.

Application filed January 5, 1897.

To all whom it may concern:

Be it known that I, J OSEPH MAIT, a citizen of the United States, residing at Oakland, county of Alameda, State of California, have invented an Improvement in Gold-Savin g Devices; and I hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to an apparatus for separating gold and valuable heavy substances from lighter sand and worthless material.

It consists of the parts and the constructions and combinations hereinafter described and claimed.

Figure 1 is a longitudinal vertical section. Fig. 2 is a cross-section on line y y of Fig. 1.

The object of my invention is to provide certain improvements in that class of apparatus which is especially designed for the dry separation of light worthless sand from heavier gold and valuable particles.

In the construction of my apparatus I employ any suitable framework A of proper shape and size, and in the upper portion of this framework is a hopper B, having an inclined bottom and a discharge slot or channel 0 at the lower end or apex, with a movable sliding gate D, by which the passage of the sand is regulated. The opposite side E of the'hopper is more nearly vertical than the side which practically forms the bottom and through which the discharge-slot is made, and the lower end of the side E is continued at the same angle to a point below the slot 0, so as to form a guide to deliver the sand properly upon the upper end of the screen F. This screen stands at an angle beneath the bottom of the hopper B and declining downwardly in the opposite direction, so that the upper end of the screen is nearest to the discharge-opening C and receives the sand and material therefrom. Across the screen F are fixed a series of segmental troughs G, having the longest incline directed upwardly along the screen to increase the holding capacity of the riffles, and a short upturned lower edge, as shown in cross-section.

The screen F is mounted upon suitable rollers or supports H, resting upon the frame, so that the screen may be given a longitudinal movement upon these supports. This Serial No. 618,004. (No model.)

movement is effected by means of an eccentric I, fixed upon a shaft J, which is journaled transversely across the frame,as shown. Power is transmitted to rotate this shaft at any desired rate of speed by means of a chain extending around a sprocket-wheel upon the end of the shaft J and thence around a chaindriving wheel L, fixed to a shaft suitably journaled to the frame and having a crank or other means for applying power thereto.

The difference in the size of the sprocketwheels is such as to multiply the speed of the eccentric-shaft to any desired degree.

Upon the opposite end of the eccentricshaft is a chain-pulley M, from which a chain passes around a sprocket-wheel N, fixed to the fan-shaft O. This'sha'ft extends through a casing P, which incloses the lower surface of the screen F, and the casing has openings upon each side within which the fans Q are adapted to revolve. These fans are made with propeller-blades which are fixed at opposite angles, so that when the fans are rotated each of them draws air in from the outside and forces it into the receiving-chamber P, where it will accumulate under considerable. pressure by reason of its being driven in from opposite sides. This air thus accumulated under pressure passes out through the meshes of the screen F and thus keeps the material upon the screen in an agitated condition, the lighter portion being lifted by the steady pressure of air and eventually dis charged over the lower end of the screen, while the heavierparticles are retained by the transverse receivers or riffles G and from which these heavier particles may be readily removed.

The operation of the machine is extremely effective in separating the gold from the sand.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A device for separating heavier and lighter particles consisting of the inclined longitudinally-oscillating screen, an oppositely-inclined hopper and a regulating-gate through which the material is supplied to the upper end of the screen, and an extension or guide between the discharge and the screen, an air-chamber supported below the screen and having inlet-openings in the sides, and

an open discharge covering the lower surface of the screen, fans having oppositely-inclined blades journaled to rotate within said openings whereby air is forced in from opposite sides, and riffles fixed transversely across the screen-surface, having a short upturned lower edge and having the longest incline directed upwardly along the screen.

2. A device for separating heavier and lighter particles of gold and sand consisting of a hopper having a discharge-slit at the bottom, a gate by which the discharge is regulated, an extension from one side of the 110pper serving to guide the discharged material, a screen supported upon hearing-rollers, an eccentric mounted upon a shaft to which 1110- tion is transmitted to rotate it, a link connecting the eccentric with the screen, trans verse riffles made in the form of upwardlypresented segments fixed to and extending In witness whereof I have hereunto set my hand.

J OSEPH MAIT. Witnesses:

S. H. NOURSE, Jnssm O. BRonIn. 

